CircuitPython to list files in SD

CircuitPython exercise to list files in SD

Connection:

                    Raspberry Pi Pico 2 W
                    =====================
                    		GP28|
                    		GND | 
                    		GP27| 
                    		GP26| 
                    		Run |
                    		GP22|
                    		GND |
                    		GP21|
                    		GP20|
    +------- SD_MISO|GP12	GP19|
    | +----- SD_CS  |GP13	GP18|
    | |             |GND	GND |
    | | +--- SD_SCK |GP14	GP17|
    | | | +- SD_MOSI|GP15	GP16|
    | | | |         +---------------+
    | | | |
    | | | |         SD Module
    | | | |         =========
    | | | | GND --- GND
    +-|-|-|-------- MISO
      | +-|-------- CLK
      |   +-------- MOSI
      +------------ CS
            3V3 --- 3V3

Exercise Code:

cpy_rpPicoW_sd.py

"""
Raspberry Pi Pico 2 W/CircuitPython 10.0.3
with SD Card module.
List files in SD.
"""
import os, sys
import board
import busio
import sdcardio
import storage

sd_miso = board.GP12
sd_cs   = board.GP13
sd_clk  = board.GP14
sd_mosi = board.GP15

info = os.uname()[4] + "\n" + \
       sys.implementation[0] + " " + os.uname()[3]
print("=======================================")
print(info)
print("=======================================")

# Init SD
sd_spi = busio.SPI(clock=sd_clk, MOSI=sd_mosi, MISO=sd_miso)
sd = sdcardio.SDCard(sd_spi, sd_cs)
vfs = storage.VfsFat(sd)
storage.mount(vfs, '/sd')

def list_dir(path, indent=0):
    """Recursive SD card walker (like a mini os.walk())"""
    for name in os.listdir(path):
        full_path = path + "/" + name
        st = os.stat(full_path)
        mode = st[0]

        if mode & 0x4000:  # directory
            print("  " * indent + "[DIR] " + name)
            list_dir(full_path, indent + 1)  # recurse into subfolder
        else:
            print("  " * indent + name)

def list_files_with_ext(path, ext):
    """Return sorted list of files in path with given extension."""
    files = []
    for name in os.listdir(path):
        full_path = path + "/" + name
        st = os.stat(full_path)
        mode = st[0]

        # check regular file (0x8000) only
        if mode & 0x8000:
            if name.lower().endswith("." + ext.lower()):
                files.append(name)

    files.sort()
    return files

# usage
list_dir("/sd")
print()

bmp_files = list_files_with_ext("/sd/bmp", "bmp")
print(bmp_files)
gif_files = list_files_with_ext("/sd/GIFs_10", "gif")
print(gif_files)